The Seismic Behavior Of Chimney Under Vertical Earthquake Action

As a burst natural disaster, earthquake has caused enormous life and property loss. Horizontal earthquake action has been generally assumed as the decisive role in damaging structures by traditional idea. According to the damage of structures under large earthquake in the past few decades, it is shown that this traditional idea is not correct and the vertical seismic action does play the major role in the damage of highrising buildings.Chimney is more important highrising building in dustries. The anti-seismic safety property of chimney is not only influence on the safety property of vicinal structures, but also the earthquake resistance and hazard mitigation of urban lifeline engineering. Chimney is sensitive to vertical seismic action as a highrising structure. So further studies on vertical earthquake actions for chimney are significant to the reliability of seismic design, and have practical value to a certain degree.Analyzing the dynamic response properties and failure behavior of chimneys under vertical earthquake inputs is the major task in this paper. Considering that earthquake is very complicated ground motion, we also study the seismic behavior of chimney under three-dimensional seismic action.1. The research progress of chimney under vertical earthquake action was addressed and the methods in calculating vertical earthquake forces in past few decades were summarized in this paper.2. Using finite element model of chimney by ANSYS, we carried out static analysis, model analysis, response spectrum analysis and elastic time-history analysis for chimney in order to study the static and dynamic response properties of high-rise chimney subjected to vertical seismic action. The results of the analysis show that the vertical stress can not be neglected completely although the horizontal seismic stress played a part of in damaging chimneys.3. Analyzing the elastic-plastic properties of chimneys with different heights and different reinforcement ratio under three-dimensional seismic action, the mechanism of the failure of R.C chimneys under earthquakes was studied. The influence of seismic wave intensity, seismic wave input dimensions, second-order effect and the damping ratio were considered in this paper.